Add Migadu domain admin with shared lists, compaction, and safer apply.

Build the Go API and React UI for managing domain denylist/allowlist/recipient
deny and spam settings, plus shared lists that import/apply across domains with
wildcard compaction, entry verification, and Migadu-friendly list encoding
(including per-domain recipient filtering and rejection bisect on apply).

web/.gitignore

@@ -0,0 +1,24 @@
+# Logs
+logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+pnpm-debug.log*
+lerna-debug.log*
+
+node_modules
+dist
+dist-ssr
+*.local
+
+# Editor directories and files
+.vscode/*
+!.vscode/extensions.json
+.idea
+.DS_Store
+*.suo
+*.ntvs*
+*.njsproj
+*.sln
+*.sw?